DEFINITION

Insomnia is described as dissatisfaction with sleep quality or quantity associated with difficulty initiating or maintaining sleep or with early morning awakening [1] [2].

Complaints often include taking longer than 30 minutes to fall asleep, staying asleep for less than 6 hours, repeated or extended awakenings, or experiencing sleep that is chronically nonrestorative or poor in quality [3] [4] [5].

Insomnia disorder is classified under the Sleep-Wake Disorders section of the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) [6].